At the end of emerging alsa-driver I got the following message: xargs: warning: a NUL character occurred in the input. It cannot be passed through in the argument list. Did you mean to use the --null option? rmdir: //lib/modules/2.6.20-ck1-sa6/kernel/sound: Directory is not empty >>> media-sound/alsa-driver-1.0.14_rc2-r1 merged. The resolution is trivial: that's because of a missing option of xargs in the last line of the ebuild. Either xargs -0 or xargs --null should be used after piped find -print0. All the 1.0.14 ebuilds and version 9999 are affected.
Thank you András, this has been addressed in the alsa-driver-1.0.14 (final) ebuild.